This invention particularly relates to shape sawing of a log, cant or similar lumber piece (collectively referred to as a log) which is curved in one plane. It is desirable to remove lumber slabs or boards from the log by sawing along the curvature to provide boards having parallel and curved faces that follow the log curve. Such maximizes the boards that can be cut from the log which are subsequently straightened. This process in general is referred to as shape sawing.
There are numerous patents that have issued on various shape sawing techniques. Such techniques include (a) feeding of the log along a curved conveyor path that is established to substantially match the curve of the log; (b) conveying the curved logs along a linear path and then continuously moving (angularly and laterally) a vertical gang of saw blades (mounted on a horizontal arbor) to orient the saws to follow the curvature of the log; and (c) a combination of the first two mentioned.
Each of the known techniques has problems, a common one of which is the need to provide special conveying systems. It is an object of the present invention to simplify the conveyor system in part by incorporating existing conveyors, e.g, sharp chain conveyors, that are typically in use for other functions preceding the sawing operation such as scanning.